[en] We report the muon spin rotation experiments on Zn substituted La_1-x Sr_x CuO₄, for four zinc concentrations y=0.0,0.0025,0.005,0.01, at strontium concentrations x=0.15,0.20. We find that T_c in the optimally doped (x=0.15) and overdoped (x=0.20) 2:1:4 decreases linearly with increasing zinc concentration. Plotted against the planar zinc concentration, the T_c's of both series seem to fall on the same line. The superconducting carrier density/effective mass ratio, n_s/m*, at first decreases linearly, rising above this line for higher zinc concentrations. This behavior may result from the localization of carriers in an area ξ_ab around each zinc atom

[en] We have performed transverse-field muon spin relaxation measurements of the Zn-substituted cuprate high-T_c superconductors: La_2-xSr_x(Cu_1-yZn_y)O₄ and YBa₂(Cu_1-yZn_y)₃O_6.63. The superconducting carrier density/effective mass n_s/m^* ratio at T→0 decreases with increasing Zn concentration, in a manner consistent with our open-quote open-quote swiss cheese close-quote close-quote model in which charge carriers within an area πξ_ab² around each Zn are excluded from the superfluid. We discuss this result in the context of Bose condensation, pair localization, and pair breaking. copyright 1996 The American Physical Society